A checkpoint leading to the U.S. Embassy compound in the Yemeni capital Saana. (Mohammed Huwais/AFP/Getty Images)

Few people beyond al-Qaeda leader Ayman al-Zawahiri could know for sure why he would order the leader of Yemen-based affiliate al-Qaeda in the Arabian Peninsula (AQAP) to stage an attack, as he's thought to have done, leading the U.S. to close 19 of its embassies after intercepting the communication.

According to Occam's razor, the simplest explanation is usually the most likely to be true, which in this case would be that Zawahiri ordered the attack because he likes to threaten U.S. embassies and occasionally tries to attack them. But al-Qaeda is a big, complex organization and alternate theories are possible. One of the most interesting comes from a terrorism analyst named Clint Watts, who argues in an article at the Web site of conservative-leaning think tank Foreign Policy Research Institute that this alleged attack may be best understood as a function primarily of internal al-Qaeda politics.

Something to keep in mind about al-Qaeda and its affiliates is that they're separated by thousands of miles, not to mention differing priorities, personnel and, potentially, missions and ideologies. Especially now that Osama bin Laden is gone, there's not quite as much tying them all together. Zawahiri is ostensibly in charge of all of those affiliates, to some degree. But Watts suggests that the group structure may be fracturing, and with it the ability of Zawahiri and "al-Qaeda Central" to lead.

In this theory, the Yemen plot would be a way for Zawahiri to reassert his leadership and to revitalize the part of the al-Qaeda network over which he has the most control. That could be about more than just Zawahiri jockeying for more of a personal role: It could also be about holding together the broader al-Qaeda network, which has always had infighting but may actually be on the verge of splitting in two.

The Yemen-based branch of al-Qaeda, once ascendent, has suffered a number of major setbacks in recent years, with top commanders and propaganda officials killed and funding drying up. To a lesser degree, so has the North African branch, which only a few months ago controlled entire swaths of Mali. And the decline of al-Qaeda's "Central" branch in Afghanistan and Pakistan is well-established.

Meanwhile, the Iraq- and Syria-based branches of al-Qaeda have been rising, capitalizing on the growing violence in both countries, on an influx of funding and growing attention within jihadist spheres. But the Syria and Iraq branches have also shown a greater willingness to buck the ostensible commanders back in Afghanistan and Pakistan. In May, when the al-Qaeda in Iraq branch tried to absorb the Syria-based Jabhat al-Nusra under its command, Zawahiri issued a "ruling" forbidding the reorganization. A few weeks later, the Iraqi leader released an audio message – they don't have PowerPoint, apparently – calling Zawahiri's ruling invalid and saying he would go ahead with the merger anyway. They're now both ostensibly under the Iraq-Syria umbrella group Islamic State of Iraq and Ash-Sham (ISIS), which, it's worth noting, began its life by openly defying Zawahiri and the al-Qaeda central command. And, even before bin Laden died, the Iraq-based al-Qaeda was known for focusing more on local and sectarian battles than on the grand "global jihad" sought by central commanders.

That may have been a step toward dividing al-Qaeda into two competing groups, according to Watts's theory. That's far from gospel among al-Qaeda watchers, but it's an interesting theory. Here, from Watts's article, is a graphic showing the possible divergence within the group:

(Clint Watts/Foreign Policy Research Institute)

If that fracture does deepen, and along the lines that Watts is predicting, here's what the two groups would look like, based on his analysis. As you can see, the "old guard" half wouldn't come out too well on its own, which helps explain why Zawahiri might want to keep them together:

(Clint Watts/Foreign Policy Research Institute)

For Zawahiri, then, perhaps reinvigorating the Yemen-based AQAP as the flagship brand with a spectacular attack might help to balance out this division and could grant him greater legitimacy as al-Qaeda's preeminent leader, perhaps preventing a split. In such a physically dispersed organization unified largely by ideology, surely perception and prestige matter a great deal in who decides to follow whom.

For Zawahiri, merely the appearance of ordering a big operation could help him with internal al-Qaeda politics. "Now the leader of the most consequential affiliate has an intimate command role in the overall organization," terrorism analyst Bruce Hoffman told the Post. "From Zawahiri’s point of view, there’s no better exemplar of the Qaeda brand than AQAP."

Even if these internal politics weren't a primary driver for Zawahiri in apparently ordering the attack, it's still a reminder of the degree to which al-Qaeda's challengers are internal, about ideology, branding, political wrangling and lines of control, not to mention the all-important funding chains. Al-Qaeda has always struggled to create an international, inter-continental network of terrorist and militant groups operating in ideological and strategic lock-step toward a never-quite-defined world-changing goal. The group's branches are certainly still dangerous, particularly in Syria and Iraq, but al-Qaeda's still-deep internal struggles should be a telling indicator of their external abilities as well.

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Comments our editors find particularly useful or relevant are displayed in Top Comments, as are comments by users with these badges: . Replies to those posts appear here, as well as posts by staff writers.